Agilent Technologies HP 8719D Service Manual page 227

Swap Samplers to Check A64 I1 Sampler
1. At A66J3 (the B sampler, see location diagram or the "Replacement
Procedures" chapter of this manual), replace the IF OUT cable with the IF
OUT cable removed
from A64J3 (the R sampler).
3. If the phase lock problem persists, the R sampler was not the problem.
Continue with "Check Open Loop Power. n
4. If the phase lock error message disappears, either the control voltage, bias
voltage, RF signal or the R sampler itself is faulty.
5. Check for about + 0.02 V on the green sampler control wire: if it is bad,
replace A5 1.
6. Check the + 15 V and -15 V bias voltages (see "A51 Interface Power
Supplies"). If they are bad, replace A51.
Note
For the HP 8722D, if 2.4 mm flexible cables and 2.4 mm power
sensors are not available, troubleshooting is possible using
3.5 mm equipment and 3.5 mm to 2.4 mm adapters, such as HP
7. If the control and bias voltages are good, use a power meter and the flexible
cable from the tool kit to troubleshoot the RF signal path.
9. Measure the M/A/D/S output power at the R CHANNEL OUT port on the
front panel.
For the HP 8719D/20D, the power should be at least -18 dBm (-13 dBm,
n
Option 007).
For the HP 8722D, the power should be at least -27 dBm (-22 dBm,
n
Option 007).
10. If the power level is correct, replace the R sampler. If the power level is not
correct, replace A58.
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Source Troubleshooting 7-7